I know this stuff seems redundant after 10 pages of comments, but I have to join the crowd and post my thoughts, too. I finally got to see it today. I gave it a 6.
It felt to me like the major thing lacking from the movie was the fact that I knew how it was all basically going to wrap up. I mean, you knew vader was going to lose against Kenobi, you knew the emporer would survive, you knew yoda would survive. You knew Padme was having twins, bla bla bla.
I totally got the Frankenstein reference at the end. I liked Yoda slamming the two imperial guards against the wall. I felt like the whole Kashyyk thing wasn't needed, as someone else commented on earlier. I liked the reference to wedge, and Grand Moff Tarkin. I liked that Lucas threw the diehard fans a little bone in those scenese.
I felt like Anakin's slide was too quick. How do you go from "No, you can't kill him, he's defenseless, it's not the Jedi way!" to killing innocent children in the same day? Totally unbelievable.
I thought it was the best of the I-III, but still doesn't hold a candle to IV-VI.